Stabilization of dairy compositions



Patented May 12, 1942 2,282,194 STABILIZATION or DAIRY COMPOSITIONSSidney Musher, New York, N. Y., assignor to Musher FoundationIncorporated, New York, N. Y., a corporation of New York No Drawing.Original application November 30, 1939, Serial No. 306,815. Divided andthis application February4, 1942, Serial No. 42295505 Claims.

meats and fish, such as bacon, mackerel, salmon and tuna fish. The yeastmay also be added to cream before pasteurizing, which cream is' thenchurned to produce butter, or to fruit ice creams and particularly tostrawberry ice cream.

Before addition,- the yeast is filtered from the beer and is drieddesirably at a temperature of over about 150 F. and preferably at somestage in the drying operation the temperature is in- I creased toapproximately 200 F. in order to kill ofi the fermentative organisms ofthe yeast.

There may alsobe utilized the water soluble constituents contained .inyeast prepared by extracting the yeast in a slightly acidified water oralcohol and then concentrated after extraction to over about totalsolids.

The water soluble extract of the yeast which is extracted by a slightlyacidified water and at a temperature between about 125. F. and 145 F. iseither before, during or after extraction rendered substantially free offermentative organisms.

It is quite important that the extract after preparation from the yeastbe concentrated to between 40% and total solids or more.

The temperature of extraction may be between about 125 F. and 145 F.provided the fermentative organisms have already been killed off in theyeast. However, where there still remains any live cells in the yeast,the extraction should proceed for the shortest possible time such as forless than 30 minutes at a temperature of not in excess of about F. andpreferably at room temperature.

As an example of the method of preparing such extract from yeast, theyeast is desirably first pressed to a paste containing in excess ofabout 30% total solids or dried or the yeast may be extracted afterhaving been skimmed off the fermented beer and then pressed to removeextraneous materials. The yeast is'desirably finely macerated or groundin order to expose the yeast cells which may then be subjected to asufficiently high temperature to kill off the fermentative organisms ofthe yeast. Preferably the yeast is heated in its moist condition to over150 F. and desirably to about 200 F.

The yeast is then mixed or agitated thoroughly with a quantity of waterfor a period of about 30 minutes at a temperature of 135 F. The time ofagitation may vary from 5 minutes to 2 hours but in order to obtain themaximum yield and the most desirable product, the time period forcontinuous agitation should be between about 45 minutes and 1 hour.

The temperature of the water at the time of the extraction should not bein excessof about 140 F. to'145 F. nor less than about F. to F.

The water used should be substantially free of minerals and desirablyfree of iron and copper. Where the water normally has a pH above 7.0, itshould be acidified to reduce the pH. Preferably, in order to obtain aclear supernatant water containing the extract, and to obtain the mostdesirable type of extract, the.pH of the water should be adjusted tobetween 4 and '7 and preferably to about 5 to 6 by addition of a mineralacid such as hydrochloric, sulphuric or phosphoric, or an organic acidsuch as acetic, tartaric, citric, etc, or by the addition of acid saltssuch as acid sulphates .or phosphates. This adjustment may take placeduring or before the extraction. The pH adjustment will also serve toincrease the rate at which insoluble material will settle out leaving aclear supernatant water portion containing the extract.

Any quantity of water may be used to produce a free flowing mixture. Onepart of yeast should preferably be mixed with about 4 parts of water byweight. Other proportions may also be used such as from 4 to 15 parts ofwater to every 1 part of yeast.

Another very satisfactory method is for the yeast to be ground or milledwith-suflicient water to produce a paste and whereby the cell structureof the yeast is so broken into as to permit the maximum solubility ofthe water extractable substances into the water. Then the pulpy aqueousmass may be pressed or centrifuged or otherwise treated to remove theaqueous solution containing the extract. Preferablythe same temperatureand acidity are employed as above. The solution may be clarified orfiltered or where additional water is added, allowed to settle out.

Where the yeast-water suspension is allowed to stand for settling out,and after the 30 minute agitation and extraction period, the solutionshould desirably be cooled by placing it in a jackuntil a substantiallyclear unfermented supernatant liquid is formed which liquid is removedby decanting, siphoning, or similar process.

The solution containing the yeast may also be subjected to a continuouscentrifuging whereby all undissolved material is removed as a continuousoperation.

The substantially clear solution thus obtained should desirably beevaporated by vacuum distillation at about 135 F. to approximatelybetween 45% and 75% solids and desirably to about 70 solids and to aBaum of 37. After the proper solids content has been reached, theextract should desirably be subjected to superheated steam in the vacuumpan in order to raise the temperature of the extract to 200 F. for about10 minutes in order to sterilize it and also retain its full stabilizingproperties for longer periods.

The evaporating temperature may vary, dependent upon whether vacuum oratmospheric pressure is used. Although it is desirable to use vacuumevaporation, evaporation at atmospheric pressure may also be employed.

The concentrated extract may also be packed in cans or other containersand sterilized at 220 F. to 250 F. for 10 to 30 minutes.

Where, due to prolonged sterilization or high heat during suchsterilization, a coagulation or precipitation is formed resulting in theproduction of insoluble matter, such precipitate may be filtered orotherwise removed. Distilled or softened water is desirable as theextracting medium and will avoid, to a large degree, such precipitationand coagulation.

Where drying is desirable, the concentrated water extract may be driedon trays, preferably under vacuum and a desirable dried product will beobtained. Drum drying is diflicult in view of the mucilaginous nature ofthe extract by means of which the extract adheres to the drum and cannotreadily be scraped off. Spray drying may less preferably be resorted toin view of the oxidation occurring during the spray drying operation.

A small quantity of the yeast and preferably its water extract inconcentrated form may be added to cream containing between 30% and 35%of butterfat in its dispersephase and the cream then churned to producebutter, in which the yeast or the yeast extract is removed with thebuttermilk leaving the butter substantially free of the added yeastmaterial but nevertheless stabilized against oxidative deterioration.

Example I a pH of 6, the water soluble portion being removed byflltration and then concentrated in a vacuum pan at 135 F. to about 70%solids or to a Baum of 37. 0.25% of this concentrated extract was addedto a 35% butterfat containing cream and the cream then pasteurized andchurned to produce butter. The butter was stored at 50 F. and comparedin keeping quality with ordinary untreated butter to which no yeastextract had been added. An improvement of 1 point in the scoring of thebutter was observed within 3 weeks which increased to about 1 pointsafter a 4 week period, over the untreated butter score.

The yeast or yeast extract may be added in any desirable amount butgenerally less than 2% and preferably under .5% is added. For all normalpurposes, as little as from 0.05% to 0.5% may be added to cream in themanufacture of butter.

Similarly the yeast and its extract may be added in the brining orcuring of meats, fish, olives and other food products and particularlyof such fatty meats and fish as bacon, mackerel, herring, sardines,salmon and tuna fish.

For example, in the brining of mackerel or in the curing of fatty bacon,from 0.05% to 2% and preferably under about 1% of the yeast or its waterextract may be added to the brine solution or with the other curingingredients and rancidity of the bacon as well as of the salt mackerelwill be very materially retarded.

Example II The extract prepared as for Example I was admixed with saltin an amount of 5% against the weight of the salt. The salt containingthe yeast extract was used in the curing of mackerel by rubbing thesalt-extract combination over the mackerel and using 60% of the treatedsalt against the weight of the mackerel. The mackerel was observed atregular intervals in comparison with mackerel with which salt alone hadbeen used in the curing and it was observed that the mackerel cured withthe treated salt was free of rancidity for a period of over 3 months,whereas the mackerel cured with the untreated salt kept free fromrancidity for a period of,only

about a month and a half.

The yeast extract may also.be utilized in an amount of between about 1%and 15% on the basis of its total weight against the weight of the saltused in the brining or curing operations.

Particularly in .the manufacture of the fruit ice creams such asstrawberry ice cream, peach ice cream and pineapple ice cream, the yeastor its extract may be added to such ice cream mix to retard thedevelopment of o'xidized off-flavors. In such ice creams, as little as0.03% to 0.3% may be added and marked stabilization is observed.

Example III To a strawberry ice cream mix was added 0.1%

of a fermentative organism-free yeast powder.

The strawberry ice cream mix was then frozen and held in storage at 15being tasted at regular intervals for off-flavor developments. It wasobserved that the strawberry ice cream containing the yeast powder wassubstantially free of off-flavor development for a period of 5 weekswhereas a lot of strawberry ice cream to which yeast powder hadnot beenadded showed the oilboard is used as wrappers for butter, lard, slicedbacon, biscuits and crackers.

It has been particularly found that where the yeast or its extract isadded to an organic matehours.

rial subject to oxidation and that organic material containing the yeastor its extract thoroughly dispersed therein subjected to an elevatedtemperature in excess of about 170 F. and desirably to about 250 F. orabove, marked improvement in keeping qualities is obtained.

For example, the yeast or its extract may be added to chopped hog fatand the chopped hog fat then rendered at a temperature of about 250 F.or above, or used in the rendering of tallow, oleo oil or lard at theelevated temperatures of rendering, or the extract may be added to creamwhich is then heated to about 180 F. and churned to produce butter,

In the manufacture of strawberry ice cream, it is desirable to add theyeast or its extract to the strawberry ice cream before the ice creammix has been heated to 145 F. or above and it is particularly desirablefor the yeast to be added to the cream used in the manufacture of theice cream and the cream then heated to about 170 F. to 180 F. andsuch-cream then used in the manufacture of the strawberry ice cream.

In the treatment of glyceride oils and fats such as lard, tallow, oleooil, cottonseed oil, corn oil, soya bean oil, castor oil, cod liver oil,tea seed oil, olive oil or other animal or vegetable oil or fat eitherin substantially crude, refined or hydrogenated condition, it isdesirable to use the finely divided yeast itself, adding the yeast, withits fermenting'orga'nisms having already been killed off, in an amountof between 0.05% and and thoroughly admixing the yeast in the oil orfat.

Example IV To bleached refined lard was added 0.1% of fermentativeorganism-free brewers yeast powder. The yeast powder was thoroughlymixed in the lard and the lard tested on the Swift Stability Apparatusby means of which air is bubbled through a 20 cc. sample of lard at 208F. until rancidity is observed. The results obtained were as follows:

Rancid after hours Untreated lard 1 Treated lard 4 Example V Chopped hogfat was rendered at 260 F. for 3 To the chopped hog fat was added beforerendering 0.1% of fermentative organismfree brewers yeast powder andthoroughly admixed with the chopped hog fat in the rendering kettle. Thelard which was rendered was compared in keeping quality with lardprepared from a similar lot of chopped hog fat to which no yeast powderhad been added.

,, Rancid after hours Lard from untreated chopped hog fat 2 Lard fromtreated chopped hog fat 1 Where the fat such as lard is to be used inthe normal distribution or storage periods and with-' out requiring thesame care that is needed where; the yeast itself is to be held.Preferably, however, the fermentative organisms have been killed off. I

As indicated above, where the yeast extract or the yeast powder with itsfermentative organisms killed off has been added to a substantially pureglyceride such as to lard, cottonseed oil, olive oil, etc., it isdesirable for the oil following the addition of the yeast thereto to besubjected to an elevated temperature in excess of about F. and desirablyto 250 F. or over.

Another feature of the present invention is that the yeast powder or itsextract may, for example, be dissolved or dispersed in a concern tratedsugar solution such as in molasses, as refinery 0r crude blackstrap orsorghum or beet molasses, and the molasses or concentrated crude sugarsolution containing the yeast then serving as the continuous phase forthe dispersion of a vitamin containing oil therein such as fordispersing cod liver oil, halibut liver oil, or other vitamin containingoil in the molasses containing the yeast. Under these circumstances, thecod liver oil or other vitamin containing oil is very materiallyimproved. in keeping quality. For example, a mixture may be prepared.comprising 5% of the yeast in molasses and the molasses containing the5% of yeast then used as. the-aqueous continuous phase for thedispersion of about 15% of cod liver oil which cod liver oil may behomogenized in the molasses containing the yeast. Desirably, the mixtureis then subjected to an elevated temperature of 250 F. or above.

In the preparation of the water extract of the yeast, where desired acarrier may be employed in the drying of the extract. For example, theconcentrated Water extract of the yeast may be mixed with condensed skimmilk, on the basis of using from 5% to 60% by weight of the extract (onits solids basis) against the solids weight of the skim milk and thethoroughly mixed combination of the extract and skim milk dried on adrum drier or otherwise dried. The skim milk absorbsthe gummycharacteristics of the extract and permits much easier drying than wherethe extract is dried alone.

There is obtained a combined action of the milk ingredients with theextract to further increase the stabilizing action of the extract. Thedrying may be done preferably on a hot roll and the dried film scrapedoff after drying. Less preferably the mixture may be dried by sprayinginto a heated chamber,

This dried combination may then very desirably be utilized for additionto dairy products such as for addition to an ice cream mix, to cream inthe manufacture of butter, or to market milk in an amount of between0.1% and 5%, for example, or for use in the manufacture of sausage orother oxidizable food compositions. Where desired, as little as 0.5% ofthe extract on its solids basis may be combined with the skim milk onits solids basis.

Other carriers may also be employed and par-' ticularly salt and sugar.The extract may, for example, be-mixed with salt or sugar using from 1%to 20% of the extract and 99% to 80% of the salt or sugar and preferablyapplying the concentrated extract to the sugar or salt crystals byspraying such extract on the crystals While they are kept at above 180F. and desirably at between 250 F. and 300 F. so that the extractdries'on the surface of the crystals of the salt or sugar.

- For example, as the salt crystals leave the kiln at 275 F., theextract containing 30% water may be heated to 170 F. and sprayed on thesalt crystals, applying 2% on the solids basis to the salt in thismanner, thereby obtaining a completely soluble product. The extract maybe applied to sugar such as to refined cane or beet sugar or to dextroseat the'centrifugals to obtain complete admixture with and absorptionupon the sugar crystals.

By applying the extract to sugar particularly,

either in crystalline form or as a concentrated solution, a sugarpreparation is obtained which may be utilized particularly whensubjected to elevated temperatures in oxidizable food compositions, suchas for addition to'dairy products, candies and confections, beveragessuch as Coca Cola and other fruit'drinks, orange juice, lemon juice, inthe canning of fruits, etc., and particularly where the sugar containingthe extract is heated to a temperature of about 250 F. or above afteraddition to thefood.

Similarly, the treated salt may be used in the manufacture of butter inplace of ordinary salt or in curing or brining operations such as in thecuring or brining of meats, fish and olives and particularly of fattymeats and fish.

Alcohol may also be used as the extractant from the yeast which has beenfreed of fermentative organisms and particularly the lower molecularweight alcohols which have been slightly acidified and with or without asmall quantity of water also present at the time of extraction.

The extract may also be mixed with fully water miscible or partlywatermiscible organic solvents such as, for example, acetone, oralcohols and particularly the higher molecular weight aliphatic alcoholssuch as butyl'alcohol, to precipitate and remove undesirable materials.If desired, it' is also possible, although less preferable, to use amixture of water and these organic solvents as extracting agents,preferably in slightly acidified condition. Or, on the other hand, theorganic solvents themselves may be utilized as the extractant followingwhich they may be evaporated to obtain the concentrate or mixed withwater to precipitate therefrom materials not desired in the finalconcentrate.

The yeast that is utilized in accordance with this invention ispreferably brewers yeast or yeast obtained during the manufacture ofbeer although yeast obtained from the manufacture of alcohol by molassesfermentation or in distillery operations may also be'utilized. Bothtop'yeast" and bottom yeast may be employed.

Dried grains containing high proportions of yeast but freed offermentative organisms or added in an amount'insuflicient to produce anyyeast odor or flavor in the food, such as in the butter, bacon orstrawberry ice cream, and generally the amount used will be less thanabout 1%.

Zymase may also be utilized, particularly in its inactive form and'afterhaving been subjected to the elevated temperature of inactivation, andpreferably in combination with a sugar and when subjected to an elevatedtemperature of over 170 and desirably over 250 F.-a1ter addition to theoxidizable composition.

The present application is a division of application Serial No. 306,815,filed November 30, 1939. The present application is limited tothe'treatment of dairy compositions whereas the patent application,Serial No. 306,815 is broadly directed to the treatment of foodcompositions.

Through copending application Serial No. 306,815, the presentapplication is a continuation in part of applications Serial No.301,758, filed October 28, 1939, now Patent No. 2,198,205 and Serial No.301,757, filed October 28, 1939, now Patent No. 2,198,206. Through saidlatter applications there is continued the subject matter ofapplications, Serial No. 268,341, filed April 17, 1939, now Patent No.2,176,024; Serial No. 249,990, filed January 9, 1939, now Patent No.2,176,027; and Serial No. 229,296, filed September 10, 1938, now PatentNo. 2,176,028.

Having described my invention, what I claim is:

1. A method of treating dairy compositions subject to oxidativedeterioration to stabilize them against oxidative deterioration whichcomprises adding thereto a relatively small proportion of a yeastmaterial selected from the group consisting of inactivated yeast and itswater and alcohol soluble extracts.

2. A method of treating dairy compositions subject tov oxidativedeterioration to stabilize them against oxidative deterioration whichcomprises adding thereto a relatively small proportion of a slightlyacidified water soluble extract of inactivated yeast.

their extracts may also be employed in a similar manner although brewersyeast is preferable.

It is also possible to form combinations in dry or paste form of theyeast or its extracts with a phosphatide of animal or vegetable originsuch as lecithin or cephalin and/or with a sugar such as dextrose orsucrose in amounts of from 1 to 5 parts of the yeast or its extract withfrom 5 to 1 parts of the phosphatide and/or sugar and then after addingsuch combination to an oil, particu- 3. A method of treating aqueousbutterfat containing dairy compositions subject to oxidativedeterioration to stabilize them against oxidative deterioration whichcomprises adding thereto a relatively small proportion of a yeastmaterial selected from the group consisting of inactivated yeast and itswater and alcohol soluble extracts.

4. A method of treating ice cream subject to oxidative deterioration tostabilize it against oxidative deterioration which comprises addingthereto a relatively small proportion of a yeast material selected fromthe group consisting of inactivated yeast and its water and alcoholsoluble extracts.

5. A method of preparing dairy butter subject to oxidative deteriorationto' stabilize it against oxidative deterioration which comprises addingto cream a relatively small proportion of a yeast material selected fromthe group consisting of inactivated yeast and its water and alcoholsoluble extracts, and then churning to form butter, the butter beingsubstantially free of the added yeast material.

6. A method of treating dairy compositions subject to oxidativedeterioration to stabilize them against oxidative deterioration whichcomprises adding thereto a relatively small proportion of a yeastmaterial selected from the group consisting of inactivated yeast and itswater and alcohol soluble extracts, and then heating the dairycomposition to a temperature in excess of F. whereby enhancedstabilization is obtained.

of dried inactivated yeast as the stabilizing agent. m

9. An ice cream stabilized against oxidative deterioration, said icecream containing a small amount of dried inactivated yeast as thestabilizing agent.

10. A strawberry ice cream stabilized against oxidative deterioration,said strawberry ice cream containing a small amount of dried inactivatedyeast as the stabilizing agent.

SIDNEY MUSHER.

